Computer enclosure cooling unit

ABSTRACT

A computer enclosure cooling unit adapted to current dimensional standards which is capable of controlled cooling of individual semiconductor devices as well as of the air circulated within the computer housing. The disclosed invention utilizes Peltier devices, a controller unit, both liquid and gaseous heat exchangers, and low cost construction methods to provide a compact, effective computer enclosure cooling system meeting the cooling needs of current high-speed, heat producing computer systems and components.

[0001] This is a continuation of U.S. application Ser. No. 09/434,873,filed Nov. 4, 1999.

BACKGROUND OF THE INVENTION

[0002] a. Field of the Invention

[0003] The present invention is related generally to the field ofcomputer enclosure cooling units. A substantial problem exists inkeeping computer enclosures cooled. Typically a computer enclosurehouses numerous semiconductor units, certain motorized units, and powersupplies, all of which tend to be in varying degrees inefficient andtherefore heat producing. Semiconductor units typically have an optimaltemperature operating range at or below room temperature (20 degreesCelsius). Most computer enclosures are air cooled with blowers or fanscirculating air from the enclosure into the ambient of the room withinwhich the computer enclosure is located.

[0004] More particularly the present invention is related to computerenclosure cooling units that utilize Peltier devices to enhance heattransfer out of the computer enclosure into the air circulated into theroom ambient. Peltier devices are well known for the transfer of heatthrough the device induced by electric current flow. Such devices areknown to be usefully adapted to enhance heat transfer out of individualsemiconductor devices by conduction.

[0005] Yet more particularly, the present invention is related tocomputer enclosure cooling units utilizing Peltier devices that cool notonly the individual semiconductor devices within the computer, butadditionally cool the ambient air within the computer enclosure. As theoperating speed of the various semiconductor devices within computersincreases, the inefficiencies and thus the heat generation of theindividual semiconductor devices, and in particular the centralprocessing unit or CPU generates dramatic quantities of heat. The excessheat generated, in turn, degrades the operation of the individualsemiconductor device further, where by a degenerative spiral ofoperating characteristics is encountered limiting the operating speed ofthe individual semiconductor unit and thus of the computer.

[0006] b. Description of the Prior Art

[0007] Computer enclosure cooling systems comprising fans and blowersare well known in the art. In fact, several improved blower systems havebeen developed which create a partial vacuum in the computer enclosure,or alternatively which provide specific ports for air flow into thecomputer enclosure from the room ambient, in order to increase thetransfer of heat out of the computer enclosure into the room ambient.However, all such prior art blower and/or fan systems encounter aproblem, the heat transfer efficiency out of the enclosure is limited bythe temperature differential between the air inside the computerenclosure and the air in the room ambient.

[0008] Peltier devices and the use of Peltier devices to transfer heatout of individual semiconductor materials and devices is well known.Further, the use of Peltier devices in circuitry to used regulatetemperatures of specific semiconductor devices is well known. However,transfer of heat out of the entirety of the enclosure, rather than justspecific semiconductor devices is need for optimal cooling of thecomputer enclosure; in that the density of switches within a specificsemiconductor device is a source of excessive heating and that thedensity of devices, both electronic and electrical, within the computerenclosure is yet another source of excessive heating.

[0009] Additionally well know are air circulation systems to transferheat out of computer enclosures. Some of these air circulation systemshave been constructed to conform to the physical standards set forcomputer drive bays. However, even the conformance of the aircirculation system to the standards set for computer drive bays fails toaddress the need for focused cooling created by the high operatingtemperatures of currently available high-density semiconductor devices.

[0010] Finally, the use of refrigeration systems to cool the entirety ofthe ambient in the room containing the computer enclosure is well known.The expense of this approach is often prohibitive, as is the physicalsize and placement of the refrigeration system components.

SUMMARY OF THE INVENTION

[0011] The instant invention is of a computer enclosure cooling unitthat utilizes Peltier devices to enhance heat transfer out of thecomputer enclosure and provides both cooling of the ambient air withinthe computer enclosure and cooling of selected individual semiconductordevices within the computer enclosure. The numerous problems noted inthe prior art cooling systems and devices are addressed in the instantinvention and the result is a highly effective, controllable system forcooling a computer enclosure which may be constructed in conformity withexisting standards.

[0012] Accordingly, it is an object of this invention to provide acomputer enclosure cooling unit which provides high efficiency coolingboth of the air circulating generally within the computer enclosure andof the specific semiconductor devices most prolifically heat generating.

[0013] It is a further object of this invention to provide a computerenclosure cooling unit which uses the controllability of Peltier devicesto regulate the temperature and heat exchange provided by the coolingunit to the computer enclosure and specific semiconductor devices.

[0014] It is a yet further object of this invention to provide acomputer enclosure cooling unit which doesn't require increased air flowrates through the computer enclosure in order to provide adequatecooling of both the enclosure air and specific semiconductor devices.

[0015] It is a yet further and final object of this invention to providea computer enclosure cooling unit which provides all of theabove-described advantages at a low cost to manufacture, install andoperate.

DESCRIPTION OF NUMERIC REFERENCES

[0016]1. Computer Enclosure Cooling Unit Housing

[0017]2. Computer Enclosure Cooling Unit

[0018]3. Computer Housing

[0019]5. CPU Cooler

[0020]9. Motherboard

[0021]7. Controller Unit

[0022]11. 5.25′ Drive Bays

[0023]13. 3.5″ Drive Bay

[0024]15. Mounting Holes

[0025]17. Ribbon Cable

[0026]19. Ambient Air Heat Exchanger Air Intake (Air Intake)

[0027]21. Ambient Air Heat Exchanger Air Exhaust (Air Exhaust)

[0028]23. Cooling Fluid Tubing

[0029]25. CPU

[0030]26. Enclosure Air Cooling Unit

[0031]27. Enclosure Air Cooling Unit Air Intake

[0032]29. Enclosure Air Cooling Unit Air Exhaust

[0033]30. Peltier Plate

[0034]31. Pump

[0035]32. Peltier Heat Exchange Unit

[0036]33. Peltier Device

[0037]34. Cooling Fluid Cooling Unit

[0038]35. Device Heat Exchanger

[0039]37. Condensate Drain

[0040]39. Ambient Air Heat Exchanger Air Flow Chamber

[0041]43. Enclosure Air Cooling Unit Blower Unit

[0042]45. Enclosure Air Cooling Unit Air Flow Baffles

[0043]47. Enclosure Air Cooling Unit Air Flow Arrows

[0044]49. Condensate Drain Flow Arrows

[0045]51. I″ Ledge Created by Extended Lower Level

[0046]53. Pettier Wiring

[0047]55. Air Flow Sensor

[0048]57. Air Temp Sensor

[0049]59. Ambient Air Heat Exchanger Air Flow Arrows

[0050]60. Ambient Air Heat Exchanger

[0051]61. Ambient Air Heat Exchanger Blower Unit

[0052]63. Ambient Air Heat Exchanger Blower Unit Wiring

[0053]64. Ambient Air Heat Exchanger Internal Walls

[0054]65. Apertures in Ambient Air Heat Exchanger Internal Walls

[0055]67. Device Cooling Fluid Flow Arrows

[0056]68. Device Cooling Fluid Chamber

[0057]69. Device Temperature Sensor

[0058]71. Thermal Paste

BRIEF DESCRIPTION OF THE DRAWINGS

[0059] While the novel features of the instant invention are set forthwith particularity in the appended claims, a full and completeunderstanding of the invention can be had by referring to the detaileddescription of the preferred embodiment(s) which are set forthsubsequently, and which are as illustrated in the accompanying drawings,in which:

[0060]FIG. 1 is a perspective view of the Computer Enclosure CoolingUnit mounted within a Computer Housing.

[0061]FIG. 2A is a top plane view of the Computer Enclosure CoolingUnit.

[0062]FIG. 2B is a lateral plane view of the Computer Enclosure CoolingUnit.

[0063]FIG. 2C is a front plane view of the Computer Enclosure CoolingUnit

[0064]FIG. 2D is a rear plane view of the Computer Enclosure CoolingUnit.

[0065]FIG. 3A is a sectional view of the Computer Enclosure Cooling Unittaken along the line 3A-3A, as shown in FIG. 2A.

[0066]FIG. 3B is a sectional view of the Computer Enclosure Cooling Unittaken along the line 3B-3B, as shown in FIG. 2A.

[0067]FIG. 4A is a cutaway perspective view of the Computer EnclosureCooling Unit displaying the Enclosure Air Cooling Unit.

[0068]FIG. 4B is a vertical sectional view of the Computer EnclosureCooling Unit displaying the Enclosure Air Cooling Unit.

[0069]FIG. 5A is cutaway perspective view of the Computer EnclosureCooling Unit with the Enclosure Air Cooling Unit removed to display theCooling Fluid Cooling Unit.

[0070]FIG. 5B is a vertical sectional view of the Computer EnclosureCooling Unit with the Enclosure Air Cooling Unit removed to display theCooling Fluid Cooling Unit.

[0071]FIG. 6A is a cutaway perspective view of the Computer EnclosureCooling Unit with the Enclosure Air Cooling Unit removed and the CoolingFluid Cooling Unit removed, to display the Peltier Heat Exchange Unit.

[0072]FIG. 6B is a vertical sectional view of the Computer EnclosureCooling Unit with the Enclosure Air Cooling Unit removed and the CoolingFluid Cooling Unit removed, to display the Peltier Heat Exchange Unit.

[0073]FIG. 7A is a cutaway perspective view of the Computer EnclosureCooling Unit with the Enclosure Air Cooling Unit removed, the CoolingFluid Cooling Unit removed, and the Peltier Heat Exchange Unit removedto display the Ambient Air Heat Exchange Unit.

[0074]FIG. 7B is a vertical sectional view of the Computer EnclosureCooling Unit with the Enclosure Air Cooling Unit removed, the CoolingFluid Cooling Unit removed, and the Peltier Heat Exchange Unit removed,to display the Ambient Air Heat Exchange Unit.

[0075]FIG. 8A is a perspective view of the Device Heat Exchange Unitmounted on a CPU.

[0076]FIG. 8B is a vertical sectional view of the Device Heat ExchangeUnit displaying the Device Cooling Fluid Chamber and fluid flow path.

[0077]FIG. 8C is a horizontal sectional view of the Device Heat ExchangeUnit mounted on a CPU.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

[0078] As seen in FIG. 1, the instant invention is of a computerenclosure cooling unit 2. The instant invention, in use, as depicted inFIG. 1, would normally be installed into a standard 5.25 inch drive bay11 in a computer housing 3. The dimensions of the computer enclosurecooling unit housing 1 are such that the unit may be readily mountedinto the space allocated to a standard hard drive unit within a computerhousing 3.

[0079] Numerous approaches to a solution of the heat generation problemspresent within computer housings 3 have been taken by the industry. Theinstant invention takes the approach of a bifurcated ventilation system,that is, the air circulating for heat exchange to the space outside thecomputer housing 3 does not mix with the air circulating for heatexchange within the computer housing 3. This is important as thehumidity condensation created by the drying effect when the air internalto the computer housing 3 is cooled could destroy the operation of theelectronic components within the computer housing 3. Additionally, theinstant invention may include cooling of individual electroniccomponents within the computer housing 3, as needed; and provides for acontroller unit 7 which may control the temperature of air circulatingwithin the computer housing 3 and the temperature of the cooling fluidor coolant flowing through the cooling fluid tubing 23 to the deviceheat exchanger 5, a liquid coolant heat exchanger which makes a direct,conductive heat exchange with the CPU 25 or other electronic componentselected for individual cooling within the computer housing 3. The CPU25 is shown in FIG. 1 to be mounted on a motherboard 9 which normallywill provide for mounting of numerous other electronic and/or electricalcomponents, any one or more of which electronic and/or electricalcomponents may be the subject of individual cooling by connection ofanother set of cooling fluid tubing 23 to another device heat exchanger5 which is disposed in heat conductive relationship thereto.

[0080] Also shown in FIG. 1 are the mounting holes 15, which facilitateconnection of the computer enclosure cooling unit housing 1 to bracketswithin the computer housing 3 which are normally present to secure unitsinserted into one of the 5.25 inch drive bays 11; the ambient air heatexchanger air intake 19 which permits passage of air from the roomambient into the computer enclosure cooling unit 2; the ambient air heatexchanger air exhaust 21 which permits passage of air from within thecomputer enclosure 1 out to the room ambient; and the ribbon cable 17which makes the electrical connection between the computer enclosurecooling unit 2 components and the controller unit 7.

[0081]FIGS. 2A, 2B, 2C, and 2D are plane views of the computer enclosurecooling unit housing 1 which show that to the rear of the computerenclosure cooling unit housing 1 are found the enclosure air coolingunit air intake 27 which permits air from within the computer housing 3to flow into the computer enclosure cooling unit housing 1; and theenclosure air cooling unit air exhaust 29 which permits air from withinthe computer enclosure cooling unit housing 1 to flow out into the airwithin the computer housing 3.

[0082]FIGS. 3A and 3B are sectional views of the computer enclosurecooling unit 2 which show that the instant invention is constructed inessentially four layers, each of which is herein considered a sub-unit.Working from the top down, the first layer is the enclosure air coolingunit 26, the second layer is the cooling fluid cooling unit 34, thethird layer is the Peltier heat exchange unit 32, and the fourth, orbottom, layer is the ambient air heat exchange unit 60.

[0083] The enclosure air cooling unit 26 is shown in detail in FIGS. 4Aand 4B. The enclosure air cooling unit 26 comprises an enclosure aircooler blower unit 43, a enclosure air cooling unit air flow baffles 45,an enclosure air cooling unit air intake 27, and an enclosure aircooling unit air exhaust 29. FIG. 4B depicts the direction of air flowinternal to the enclosure air cooling unit 26 by arrows 47. Alsoprovided by the enclosure air cooling unit 26 is the upper aperture of atubular condensate drain 37. The lower surface of the enclosure aircooling unit 26 is beveled, as indicated by the condensate drain flowarrows 49 in FIG. 4B, in the preferred embodiment to cause drainage ofcondensate from the cooled air within the enclosure air cooling unit 26,into the condensate drain 37, through the cooling fluid cooling unit 34and the Peltier heat exchange unit 32, to be discharged into the ambientair heat exchanger 60 where the condensate is evaporated into the heatedair and discharged into the ambient of the room containing the computerhousing 3.

[0084]FIGS. 5A and 5B are two views of the cooling fluid cooling unit 34of the preferred embodiment of the instant invention. The cooling fluidcooling unit 34 comprises a cooling fluid chamber 35, comprising thespace between the enclosure air cooling unit 26 and the Peltier heatexchange unit 32 that is within the computer enclosure cooling unithousing 1, containing cooling fluid tubing 23 which is coiled within.The tubular cooling fluid chamber 35 of the preferred embodiment is inheat conductive contact with the cold side of the Peltier devices 33contained in the Peltier heat exchange unit 32 as shown in FIGS. 6A and6B; and further in heat conductive contact with the lower surface of theenclosure air cooling unit 26. The cooling fluid cooling unit 34provides a pump 31 to circulate the cooling fluid within the coolingfluid tubing 23. Construction of the preferred embodiment provided aledge 51 upon which the pump 31 was mounted within the cooling fluidcooling unit 34.

[0085]FIGS. 6A and 6B are two views of the Peltier plate 30 of thepreferred embodiment. The Peltier plate 30 comprises a plurality ofPeltier devices 33 in electrical communication with the controller unit7 through the ribbon cable 17. The lower surface of the Peltier plate 30is comprised of heat conductive material, metal in the preferredembodiment, and such lower surface is in heat conductive contact withthe hot side of the Peltier devices 33.

[0086]FIGS. 7A and 7B are two views of the ambient air heat exchanger60. The ambient air heat exchanger 60 provides, in the preferredembodiment, two ambient air heat exchanger blower units 61, ambient airheat exchanger internal walls 64, two ambient air heat exchanger airintakes 19, and two ambient air heat exchanger air exhausts 21. In thepreferred embodiment, spacing between the ambient air heat exchangerinternal walls 64 provides ambient air heat exchanger internal air flowchambers 39, and air flow, indicated by ambient air heat exchanger airflow arrows 59, is continuous between the ambient air heat exchangerinternal air flow chambers 39 by passing through apertures 65 in theambient air heat exchanger internal walls 64. All materials in theambient air heat exchanger 60 are, in the preferred embodiment,comprised of heat conductive materials, arranged in a maze, andfacilitate the transfer of heat from the hot side of the Peltier devices33 into the air flow which discharges out of the ambient air heatexchanger air exhausts 21 into the room ambient.

[0087]FIGS. 8A, 8B and 8C are of the device heat exchanger 5 which, inthe preferred embodiment is mounted on a CPU 25, although the particularsemiconductor device upon which the device heat exchanger 5 is mountedmay change with the needs of the particular computer being cooled.Additionally, there may be a plurality of device heat exchangers 5 witheach such heat exchanger being mounted on a separate semiconductordevice in a situation where multiple semiconductor devices within aparticular computer housing 3 require individual cooling. Finally, it iscontemplated that in another preferred embodiment, the device heatexchanger 5 may be integrally a part of the semiconductor device suchthat the semiconductor packaging includes a device heat exchanger 5 andfittings for attachment of cooling fluid tubing 23.

[0088] As seen in FIG. 8A, the cooling fluid flow within the coolingfluid tubing 23 is in fluid communication with the interior of thedevice heat exchanger 5. Such communication may be attained by attachingor connecting the cooling fluid tubing 23 to the device heat exchanger5, or by simply having the cooling fluid tubing 23 be a continuoustubular construction with device cooling fluid chamber 68 within thedevice heat exchanger 5. In the preferred embodiment, as shown in FIG.8B, the interior of the device heat exchanger 5 is a maze of fluidbaffles creating a device cooling fluid chamber 68 which is designed tolengthen the path taken by the cooling fluid in order to maximize theheat transfer between the cooling fluid and the device heat exchanger 5and thus to the thermal paste 71 and the CPU 25. FIG. 8C shows theattachment of the device heat exchanger 5 to the CPU 25 as being simplya pressed fit of the thermal paste 71, which fills a cavity in thebottom structure of the exterior of the device heat exchanger 5, ontothe top of the CPU 25. This press fit of the thermal paste 71 onto theCPU 25 was chosen because many currently available CPUs 25 have a heatsink structure built onto their packaging in order to dissipateexcessive heat. The thermal past 71 will conveniently mold itself aroundthe heat sink structure. Additionally, a device temperature sensor 69 isshown in FIG. 8C of the preferred embodiment. The device temperaturesensor 69 is in electrical communication with the controller unit 7which uses various sensor feedbacks from the computer enclosure coolingunit 2 to control the speed of the enclosure air cooling unit blowerunit 43, the speed of the pump 31, the speed of the ambient air heatexchanger blower unit 61, and the number of Peltier devices 33 which areturned on as well as the current flow through each such turned onPeltier device 33. The preferred embodiment of the computer enclosurecooling unit 2 includes several sensors, air flow sensors 55, airtemperature sensors 57, and a device temperature sensor 69.

[0089] In operation, the preferred embodiment of the instant invention 2heat is discharged from the computer enclosure cooling unit 2 and intothe ambient of the room within which the computer housing 3 sits bycirculating the ambient air from the room within which the computerhousing 3 sits through the ambient air heat exchanger 60. By definition,the temperature of the ambient air of the room within which the computerhousing 3 sits is room temperature, and a breakdown of the temperaturecontrol system in the room's ambient air outside the computer housing 3is not expected to be compensated for by the instant invention althoughvariation of the room's ambient air temperature can be compensated forover a large range of room temperatures by the instant invention.Typically, the ambient air in the room containing the computer housing 3can be expected to have a reasonable humidity, something less than onehundred percent. Thus, the heat transfer from the computer enclosurecooling unit 2 to the ambient air within the room will cause anexpansion of the heated air and a localized decrease in the humidity.This localized, within the ambient air heat exchanger 60, is utilized inthe instant invention to evaporate the condensate drained into theambient air heat exchanger 60 from the enclosure heat exchanger throughthe condensate drain 37. Additionally, the flow rate of the aircirculating within the ambient air heat exchanger 60 may not be greaterthan the flow rate of the air circulating within the enclosure heatexchanger in order not to create a low pressure region at the lower endof the condensate drain 37 which would interfere with the preferreddirection of condensate flow through the condensate drain. The hot sideof the Peltier devices 33 are in heat transfer communication with theair circulating within the ambient air heat exchanger 60. In thepreferred embodiment, this heat transfer communication is accomplishedby construction of the Peltier plate 30 in such fashion that the hotside of the Peltier devices 33 are in physical contact with the heatconductive metal which simultaneously comprises the bottom of thePeltier plate 30 and top of the ambient air heat exchanger 60. Ambientroom air circulated through the ambient air heat exchanger 60 is therebyheated by contact with the Peltier plate's 30 bottom surface which isthe ambient air heat exchanger's 60 upper surface. Circulation of theair within the ambient air heat exchanger 60 is assured by the presenceof the ambient air heat exchanger blower units 61 and the arrangement ofair deflection baffles (the ambient air heat exchanger internal walls 64of the preferred embodiment). Greater heat exchange may be achieved bynumerous other arrangements of the air deflection baffles, but in thepreferred embodiment the ambient air heat exchanger internal walls 64(baffles) simply form a maze, lengthening the path taken by thecirculating air, by using strips of sheet metal as the ambient air heatexchanger internal walls 64 with apertures 65, which are stamped out ofthe strips, for air flow in order to decrease construction costs.

[0090] The Peltier heat exchange unit 32 of the preferred embodimentcomprises a Peltier plate 30 whose bottom surface is constructed of heatconductive metal to which the hot side of the Peltier devices 33 arephysically mounted and a top surface constructed of heat conductivemetal to which the cold side of the Peltier devices 33 are physicallyconnected. Thus the Peltier heat exchange unit 32 simply transfers heatthrough the Peltier devices 33 from the top surface of the Peltier heatexchange unit 32 to the bottom surface of the Peltier heat exchange unit32. The top surface of the Peltier heat exchange unit 32 is, in thepreferred embodiment constructed of a heat conductive sheet of metalwhich also serves as the bottom surface of the cooling fluid coolingunit 32, a liquid coolant heat exchanger. The rate of heat transferbetween the top surface of the Peltier heat exchange unit 32 and thebottom surface of the Peltier plate 30 and thus of the Peltier heatexchange unit 32 is controlled by the number of Peltier devices 33 thatare switched on and the current flow that is provided to each individualPeltier device 33. The preferred embodiment provides a controller unit 7which has as inputs the outputs of the various sensors within thecomputer enclosure cooling unit 1 and has as outputs the currentsupplied to the ambient air heat exchanger blower units 61, the currentsupplied to the pump 31, the current supplied to the enclosure aircooling blower unit 43, as well as the current supplied to each of thePeltier devices 33. All of the inputs and outputs of the controller unit7 are electrically connected to the various sensors and controlleddevices through the ribbon cable 17. The controller unit 7 of thepreferred embodiment is a computer card containing programmablecircuitry with a graphical user interface permitting the computeroperator to make settings for optimum computer enclosure andsemiconductor device temperatures. Clearly, the controller unit 7 may beas simple as a set of voltage and current dividers or switches preset toan average desirable set of operating conditions or as sophisticated ascircuitry driven by artificial intelligence to continually adjust airflow rates, fluid flow rates, and the number, identity, and current flowthrough individual Peltier devices 33 in order to continually maintainoptimal operating temperature for a particular semiconductor device andambient air temperature within the computer housing 3.

[0091] While a single Peltier plate 30 is utilized in the preferredembodiment, the enhanced heat transfer between sub-units of the computerenclosure cooling unit 2 made possible by the Peltier devices 33 may beadvantageously utilized between multiple sub-units. For example aPeltier plate 30 could additionally be inserted between the coolingfluid cooling unit 34 and the enclosure air cooling unit 26. Or, in aslightly different configuration, the heat conductive surface which isthe lower surface of the cooling fluid cooling unit 34 in the preferredembodiment could be utilized for both fluid cooling and air cooling byeither splitting the surface between the two functions or byinterspersing the air circulation areas and the fluid circulation areasover the single heat conductive surface. In this fashion, there would beno distinct sub-unit for the enclosure air cooling unit 26, there wouldrather be a single combined enclosure air cooling unit 26 and coolingfluid cooling unit 34. For purposes of decreasing the height and spaceconsumption of the computer enclosure cooling unit 2, such sharing ofthe heat conductive surface which is the lower surface of the coolingfluid cooling unit 34 may be advantageous. Such utilization of multiplePeltier plates 30 or of shared heat exchange surfaces do not depart fromthe teachings of the preferred embodiment.

[0092] The fluid heat exchanger (the cooling fluid cooling unit 34 ofthe preferred embodiment) is comprised of heat conductive tubing inphysical contact with a floor which is the heat conductive sheet metalcomprising the upper surface of the Peltier heat exchange unit 32 andwith a ceiling which is the lower surface of the heat conductive sheetmetal comprising the lower surface of the enclosure air cooling unit 26.Thus fluid cooling takes place by heat exchange from the cooling fluidto the heat conductive tubing (the cooling fluid chamber 35 of thepreferred embodiment) in which the cooling fluid is contained, from theheat conductive tubing to the heat conductive sheet metal comprising thelower surface of the cooling fluid cooling unit 34, from the heatconductive lower surface of the cooling fluid cooling unit 34 to thecold side of the Peltier devices 33 that are in physical contact withthe underside of the heat conductive sheet metal that is the lowersurface of the cooling fluid cooling unit 34, across the Peltier devices33 from the cold side to the hot side, from the hot side of the Peltierdevices 33 to the lower surface of the Peltier plate 30, from the upperside of the heat conductive metal comprising the lower surface of thePeltier plate 30 to the air circulating within the ambient air heatexchanger 60, and from thence is exhausted out through the ambient airheat exchanger air exhaust 21 out into the ambient of the roomcontaining the computer housing 3. The cooling fluid flow directionwithin the device heat exchanger 5 is shown in FIG. 8B by device coolingfluid flow arrows 67 thus the direction of fluid flow within the coolingfluid tubing 23 is defined. As seen in FIG. 3, the cooling fluid flowsout of the cooling fluid cooling unit 34 of the computer enclosurecooling unit 2 through the cooling fluid tubing 23 and is circulatedthrough a device cooling fluid chamber 68 (shown in FIG. 8) which is inheat exchange communication with a semiconductor device, in thepreferred embodiment a single CPU 25. There may be, by obviousmodification of the cooling fluid tubing 23, a plurality of the deviceheat exchangers 5 cooling a plurality of semiconductor devices. Thedevice heat exchanger 5 of the preferred embodiment is simply a fluidflow maze whose baffles and walls are constructed of heat conductivematerial. Numerous baffle configurations may be utilized to optimizeturbulence and/or lengthen the effective fluid flow path in order tooptimize heat transfer between the cooling fluid and the heat conductivewalls and baffles which form the device cooling fluid chamber 68 of thedevice heat exchanger 5. The device heat exchanger 5 is in heat exchangecommunication with the semiconductor device to be cooled or temperaturecontrolled. The preferred embodiment monitors the temperature of thesemiconductor device being cooled with the device temperature sensor 69and utilizes thermal paste 71 to both affix the device heat exchanger 5to the semiconductor device (CPU 25 in the preferred embodiment) beingcooled and enhance heat transfer between the semiconductor device beingcooled and the cooling fluid being circulated through the cooling fluidtubing 23 and the device cooling fluid chamber 68 within the device heatexchanger 5. Further, the thermal paste 71 serves to both put the devicetemperature sensor 71 in heat flow communication with the semiconductordevice being cooled and to affix the device temperature sensor 71 to thedevice heat exchanger 5.

[0093] Heat flow communication between the cooling fluid within thecooling fluid cooling unit 34 and the heat conductive materialcomprising the lower surface of the enclosure air cooling unit 26 actsto provide a cool surface for heat exchange with the air circulatingwithin the enclosure air cooling unit 26. The preferred embodiment,created with cost considerations foremost in mind, utilizes simple heatconductive sheet metal for the surfaces between the enclosure aircooling unit 26 and the cooling fluid cooling unit 34, between thecooling fluid cooling unit 34 and the Peltier plate 30, between thePeltier plate 30 and the ambient air heat exchanger 60, and for theconstruction of the computer enclosure cooling unit housing 1 whichserves as the outer walls of all sub-units as well as the upper surfaceof the enclosure air cooling unit 26 and the lower surface of theambient air heat exchanger 60. This construction of the computerenclosure cooling unit housing 1 from heat conductive sheet metal isconsistent with current standardized size, shape and materials forperipherals intended to be installed, as the preferred embodiment is, ina 5.25 inch drive bay 11; but is non-optimal as the heat conductivesheet metal provides heat flow communication in a negative feedback looparound the various sub-units of the computer enclosure cooling unit 2and thereby creates substantial inefficiencies. A second embodiment ofthe instant invention provides that the computer enclosure cooling unithousing 1 be constructed of non-heat conductive materials whilemaintaining the use of heat conductive material for the surfaces betweenthe enclosure air cooling unit 26 and the cooling fluid cooling unit 34,between the cooling fluid cooling unit 34 and the Peltier plate 30,between the Peltier plate 30 and the ambient air heat exchanger 60.

[0094] The enclosure air cooling unit 26 of the preferred embodimentprovides a minimum of air baffles for heat exchange to the aircirculating within it. This construction has been found to be adequateto provide modest cooling of the interior of the computer housing 3.Current art for the cooling of the interior of computer housings 3depends on air leakage into the enclosure formed by the computer housing3 and fans to exhaust that air which is leaking in. Some prior artspecifically provides for air flow into the enclosure formed by thecomputer housing 3 from the ambient in the room enclosing the computerhousing 3. However, enhanced cooling of the interior of the computerhousing 3 can be achieved by increasing the turbulence of the air andincreasing the number and complexity of arrangement of the air baffleswithin the enclosure air cooling unit 26. Enhanced cooling of the airexhaust into the interior of the computer housing 3 from the enclosureair cooling unit 26 raises the possibility of condensate forming withinthe interior of the computer housing 3 and thereby creating shortsaround the various electrical and electronic components therein. Suchpossibility of condensate forming is created by the interaction of thecool, partially dried, air exhaust into the interior of the computerhousing 3 from the air exhaust 29 of the enclosure air cooling unit 26with the relatively moist air leaking into the interior of the computerhousing 3 from the ambient in the room containing the computer housing3. This possibility of condensate formation within the interior of thecomputer housing 3 can be substantially eliminated through the use ofpositive air pressure within the interior of the computer housing 3.Positive air pressure would force air leakage out of the interior of thecomputer housing 3, thereby eliminating the source of humidity in theair interior to the computer housing 3. Positive air pressure can beachieved by moving the air input to the enclosure air cooling unit 26such that it permits air intake from the ambient air in the roomcontaining the computer enclosure rather than from the interior of thecomputer housing 3. Accordingly, a third embodiment of the instantinvention provides for the enclosure air cooling unit air intake 27 tobe located such that air is input to the enclosure air cooling unit 26from the ambient air in the room containing the computer housing 3 andnot from the interior of the computer housing 3. In the thirdembodiment, it is necessary that the local air circulation paths createdwithin the ambient air of the room containing the computer housing 3 bythe air intake to the enclosure air cooling unit 26 on the one hand andthe air exhaust from the ambient air heat exchanger 60 on the other handbe kept apart and distinct.

[0095] Cooling of the air within the enclosure air cooling unit 26,whether configured as in the preferred embodiment or in the thirdembodiment, creates a condensate on the cooled surface(s) where the heatexchange with the circulating air takes place. In the preferredembodiment the lower surface of the enclosure air cooling unit 26 isbeveled or sloped toward a condensate drain 37. The condensate drain 37comprises a tube having its upper end opening in the lower surface ofthe enclosure air cooling unit 26 and its lower end opening in the uppersurface of the ambient air heat exchanger 60. The condensate drain 37 isideally comprised of non-heat conductive materials, alternatively, thecondensate drain 37 may be heat insulated from the heat conductivesurfaces that it passes through. Freezing of the condensate within thetube comprising the condensate drain 37 as it passes through the uppersurface of the Peltier plate 30 must be avoided. A yet third, and not asdesirable, solution to avoid condensate freezing is to make the tubingcomprising the condensate drain 37 highly heat conductive such thatefficiency of the Peltier plate 30 is sacrificed in the vicinity of thecondensate drain's 37 passage through the upper surface of the Peltierplate 30 by heat feedback from the lower surface of the Peltier plate30.

[0096] A fourth embodiment of the instant invention provides that theair exhaust from the computer housing 3, having been cooled by the airexhaust from the enclosure air cooling unit air exhaust 29, is input tothe ambient air heat exchanger air intake 19. Thus a single path for airflow from and to the ambient air within the room containing the computerhousing 3 is established. Greater efficiency of heat exchange over theentirety of the computer enclosure cooling unit 2 can be achieved by thefourth embodiment, but at a cost of increased tubing or piping tocontain the flow of air from the air exhaust of the enclosure aircooling unit 26 to the ambient air heat exchanger air intake 19.

[0097] A yet fifth embodiment of the instant invention provides thatboth the air exhaust from the computer housing 3 is input to the ambientair heat exchanger air intake 19 and that the air intake to theenclosure air cooling unit 26 be positioned to permit air intake fromthe ambient air in the room containing the computer housing 3 and notfrom the interior of the computer housing 3. The fifth embodiment, incombination with the above-described possible enhancements to the airbaffle configuration of the enclosure air cooling unit 26 provides asuperior computer enclosure cooling unit 2, albeit at greater cost.

[0098] While the preferred embodiments of the instant invention havebeen described in substantial detail and fully and completelyhereinabove, it will be apparent to one skilled in the art that numerousvariations of the instant invention may be made without departing fromthe spirit and scope of the instant invention, and accordingly theinstant invention is to be limited only by the following claims.

I claim:
 21. An enclosure cooling unit which comprises a first heatexchanger, a second heat exchanger, a third heat exchanger, and one ormore Peltier devices; wherein said first heat exchanger transfers heatfrom said enclosure cooling unit to the ambient air outside saidenclosure, said second heat exchanger transfers heat from the air withinsaid enclosure to said enclosure cooling unit, said third heat exchangertransfers heat from cooling fluid circulating within said enclosure tosaid ambient air, said one or more Peltier devices transfer heat fromsaid second heat exchanger to said first heat exchanger, and said one ormore Peltier devices transfer heat from said second heat exchanger tosaid third heat exchanger.
 22. The invention of claim 21 additionallycomprising one or more additional heat exchangers wherein said enclosureadditionally contains one or more heat producing components, and whereineach of said additional heat exchangers transfers heat from one or moreof said heat producing components to said cooling fluid.
 23. Theinvention of claim 21 additionally comprising a controller unit andsensors wherein said sensors detect various temperature and flow rateswithin said enclosure cooling unit, said sensors provide informationregarding said detected temperature and flow rates to said controller,said controller provides voltages and currents to electrical and/orelectronic components within said enclosure cooling unit, and saidcontroller utilizes said detected temperature and flow rates todetermine said voltages and currents.
 24. An enclosure cooling unitcomprising a first heat exchanger, a second heat exchanger, a third heatexchanger, and one or more Peltier devices; wherein said first heatexchanger transfers heat from said enclosure cooling unit to the ambientair outside said enclosure, said second heat exchanger transfers heatfrom the air within said enclosure to said enclosure cooling unit, saidthird heat exchanger transfers heat from cooling fluid circulatingwithin said enclosure to said enclosure cooling unit, and said one ormore Peltier devices transfer heat from said second heat exchanger tosaid first heat exchanger.
 25. The invention of claim 24 additionallycomprising one or more additional heat exchangers wherein said enclosureadditionally contains one or more heat producing components, and whereineach of said additional heat exchangers transfers heat from one or moreof said heat producing components to said cooling fluid.
 26. Theinvention of claim 23 additionally comprising a controller unit andsensors wherein said sensors detect various temperature and flow rateswithin said enclosure cooling unit, said sensors provide informationregarding said detected temperature and flow rates to said controller,said controller provides voltages and currents to electrical and/orelectronic components within said enclosure cooling unit, and saidcontroller utilizes said detected temperature and flow rates todetermine said voltages and currents.
 27. An enclosure cooling unitcomprising a first heat exchanger, a second heat exchanger, a third heatexchanger, and one or more Peltier devices; wherein said first heatexchanger transfers heat from said enclosure cooling unit to the ambientair outside said enclosure, said second heat exchanger transfers heatfrom cooling fluid circulating within said enclosure to said enclosurecooling unit, said third heat exchanger transfers heat from the airwithin said enclosure to said cooling fluid, and said one or morePeltier devices transfer heat from said second heat exchanger to saidfirst heat exchanger.
 28. The invention of claim 27 additionallycomprising one or more additional heat exchangers wherein said enclosureadditionally contains one or more heat producing components, and whereineach of said additional heat exchangers transfers heat from one or moreof said heat producing components to said cooling fluid.
 29. Theinvention of claim 27 additionally comprising a controller unit andsensors wherein said sensors detect various temperature and flow rateswithin said enclosure cooling unit, said sensors provide informationregarding said detected temperature and flow rates to said controller,said controller provides voltages and currents to electrical and/orelectronic components within said enclosure cooling unit, and saidcontroller utilizes said detected temperature and flow rates todetermine said voltages and currents.
 30. The invention of claim 27wherein said one or more Peltier devices transfer heat from said thirdheat exchanger to said second heat exchanger.
 31. The invention of claim27 wherein said one or more Peltier devices transfer heat from saidthird heat exchanger to said first heat exchanger.